Additive color and Subtractive color

During the Giclee process, a graphic designer runs into two main color models. These color models are known as additive color and subjective color. To explain and differentiate the two, one must understand the involvement with the two. I will start by explaining what additive color is.

An additive color model involves light emitted directly from a source of illuminant of some sort. The additive reproduction process usually uses red, green and blue light to produce the other colors. By combining one of these additive primary colors with another in equal amount produces the additive secondary colors known as cyan, magenta, and yellow. Combing all the three primary lights (colors) in equal intensities produces white. Varying the luminosity of each light (color) eventually reveals the full gamut of those three lights (colors). Computer monitors and televisions are the most common application of additive color.

Results obtained when mixing additive colors are often counterintuitive for people accustomed to the more everyday subtractive color system of pigments, dyes, inks and other substances which present color to the eye by reflection rather than emission. For example, in subtractive color systems, green is a combination of yellow and blue. In additive color, red+green= yellow and no simple combination will yield green. It should be noted that additive color is a result of the way the eye detects color, and I not a property of light. There is a vast difference between yellow light, with a wavelength of approximately 580 nm, and a mixture of red and green light. However, both stimulate our eyes in a similar manner, so we do not detect that difference.

Additive color is simply what you see on your monitor before printing. After a Graphic Designer has created their final render of the art piece or product, the file will go through a subjective process in order to make the final rendering.

The printer is a subjective color model, which mixes and combines inks to create the visual.

Subtractive color systems start with a white medium, such as the canvas or paper to “mimic” light. Color inks, paints or films placed between the viewer and the light source or reflective surface (such as white paper) subtract wavelength from the white, and make a color.

Conversely, additive color systems start with no light (black), while subjective color systems start with a light source, such as white paper. Light sources add wavelength to make a color. In either an additive or subtractive system, the three primary colors are always needed to match humans’ trichromatic color vision caused by the three types of cone cells in the eye.

By explaining the differences between light and paper, I hope this will explain the differences between what is on screen and what the final printed product is. Nowadays, the gamut precision is almost a perfect match to what additive colors a person sees on screen to its final subtractive colors printed.